Heat oven to 350 degrees.
Use a mallet to tenderize the chicken and make the same thickness. Pat dry.
Sprinkle taco seasoning on the chicken and press into the meat.
Heat the oil in a large skillet and fry the chicken 4-5 minutes on each side.
Remove the chicken and let cool. Cut into bite sized pieces or shred with forks.
In the same skillet, saute the onions on medium heat for 5 minutes or until golden brown. Set aside.
In the same skillet, heat the enchilada sauce over low heat for 2-3 minutes.
Turn off heat. Ladle 2 cups of sauce into the bottom of a 9x13 casserole dish.
One at a time, dip a tortilla into the sauce, covering it completely.
Scoop some chicken, a spoonful of onions, and a sprinkle of cheese onto the tortilla.
Wrap tightly and place into the casserole dish. Repeat with remaining tortillas.
Pour remaining green sauce on top of enchiladas and sprinkle with cheese.
Bake at 350 degrees for 30 minutes or until hot and bubbly.
Let cool for 10 minutes to firm up. Serve warm.
Optional toppings include: salsa, pico de gallo, guacamole, sour cream, cilantro, etc.